Hand-hole cover



W. W. HOLLAND AND F. J. GAINER.

HAND HOLE COVER.

APPLICATION FILED DEC. 19, 19l9.

mum Ma 4,1920.

UNITED STAT s PATENT OFFICE.

; 'WI-LLIAM w. HOLLAND AND FRANK :r. GAINER, or woonm-vnn, Tumors.

HAND-HOLE COVER.

. Specification of Letters Patent.

Patented May 4,1920.

Applioationfiled December ,19, 1919. Seria1 No.. :3 46, d9G.

To all whom it mag concern:

Be it known 'that'we, WILLIA "W. Hon- LAND, a resident of Woodriver,county of Madison, State'of Illinois, and F ANK J. GAINER,,a resident ofWoodriver, county of Madison, Statejof Illinois], both citizens of theUnited States of America, have invented certain new and usefulImprovements, in Hand-Hole Covers, of which the following is aspecification.

Various dev ces v have been designed and used for closing the handjholesiin; the headers of water tube boilers, and highpressure oilstills, These are all subject tocertain defects, so that. no one ofthose which is in use has been found, in any considerable measure,foolproof .or satisfactory, so that it could be generally adopted ,aswholly suited to the purpose in question, having particular reference tothe application of the device, to high pressure tubular oil stills usedfor cracking oils in the manufacture of gasolene. Screw plugs, which aremost generally used, have the obvious defect that the threads may becrossed when the plugs are inserted, or threads otherwise in a weakenedcondition, may strip, causing the plug to blow out,, releasing thecontents of the still, and causing disaster of a nature which is uitefamiliar.

With .theordinary type of hand hole covers, clampedfin the usual manner,z. e. by means of a crab clamp, fatal results from blowing out of thegaskets,-the actual effect being identical with, that in the caseof thefailure of screw plugs or covers are not infrequent. V The presentinvention relates to. a type of hand hole cover in which the closurebecomes tighter as .the internalpressure increases. This isaocomplishedflbyforminga tapered P g JW hiS preferabl hollow, beingformed of sheet steel. Such plug may be inserted from th inside of theheader.

To those familiar withthe operation of tubular pressure stills,theflquestion arises as to what prevents such a plug from beingdislodged, should it receive even a slight blow, as from a fallinghammer, wrench, orany ofthetoolsused around such plants. Also there isthe danger that such a plug will be blown in incase of explosion insideof the cover doors adjacent to theheader or even in the vicinity of thestill, as suchv coverdoors and the header, owing to an accumulation ofinflammable gases and air in the proportions to form explosive mixtures.The concussion would dislodge the tapered plugs referred to, and. causepthe contents of the still to be released, resulting in a fire, which,wouldprobably destroy the still and plant. The probability that theplugs maybe thus blown or knocked in is increased-by the fact that theinternal pressure is'not always high.

Anotherelement in the situation; having the sametendency is; the tubesare inclined to thehorizontal in pressure stilllconstruction, the anglebeing usuallyfrom 20 to 30 degrees, the header, being at right angles tothe tubes is also. set at an. angle with the vertical plane. This meansthat the plugs, as inserted,.are. turnedupward at a s milar angle,giving thema correspondingly increased tendency to fall out whenloosened. The only means of preventing this is the friction between thetwo tapered surfaces, 2'. e. that of the hole and the plug, and theinternal pressure. As the still isnot always under pressure when it isfull of oil, a slight tap on one of these plugs or a; mild explosionwould, at certain times, result in the destruction of the plant, oratleast in a disastrous fire.

. Inview of the conditions, thus described, the applicants have.constructed a tapered hand hole plug or coverwhich isinserted, small endfirst, from within the header, and therefore becomes more securelyseated and tighter, the greater the internal pressure, and to guardagainst and eliminate the danger from causes whichv may tend to loosenthe plug and thrust it inward, releasing the contents of thestill, the,applicants have supplied this hand hole ,cover or plug with fasteningmeansadaptedto engage the plug, and the outside surface of the wallofthe header, the fastening means being of greater dimension than thehole.7

While we have shown such fastening means in the form of. a locking pin,particularly adapted-to this purpose, and also in the form of a nutengagingthe thread on the end of the plug, this fastening means may bein any preferred or convenient form, the object being to provide, inconnection with a header wall, having a hand hole opening, a taperedplug or closure of a cross section at its large end greater than theopening and being adapted to be inserted from within, so that itprotrudes through' the wall, and means of greater dimension than theopening for fastening it on the inside of the wall, and preventing thesmall end of the plug from being withdrawn' the invention.

In the drawings,

' Figure 1 is a section through the header wall taken on the verticaldiameter of a hand hole, showing a vertical central section of a handhole plug, closing the hand hole.

F ig.-2 is an elevation, looking at the same from the outside, bothViews being fragmentary as to the header wall.

Fig. 3 is a section taken through both walls of a header, the two wallsbeing fragmentarily shown, and the sections being on the verticaldiameter of a tube, and hand hole both 'fragmentarily shown, and thehand hole cover being shown in vertical central section.

Referring to the drawings by numerals,

the header wall, 1, the inside being to the left as indicated by theshading, has a hand hole in alinement with each tube as shown. The holesare preferably tapered so that the surface presented to the plugs is aconical frustum, the larger section or base being toward the inside ofthe header,i. 0. toward the left in Fig.1, the small end aeing turnedoutward. Seated in this hand hole or opening, 2, as shown, is a taperedplug or cover, 3, the surface of which is also a conic section orfrustum, the base or larger end, 4-, which is larger than the opening,2, being toward the inside of the header. The small end, 5, as'shownprotrudes beyond the outer surface, 6, of the wall, 1. This plug ispreferably hollow, and formed by pressing from sheet metal.

As the openings are always made large enough tov admit the hand, suchcovers or plugs having been passed inside the header, are convenientlyinserted from within. The small end of the plug, which protrudes outwardthrough the opening, extending be yond the outer surface of the headerwall, is provided with fastening means, engaging the outer surface ofthe wall to prevent .the plug from being unseated, blown in, or fallingby gravity, or from being otherwise displaced from the opening when thestill or boiler is in operation, or at any time against the will of theoperator. In the present instance, 2'. e. as shownin Figs. 1 and 2, thismeans consists of .a pin, 7. seated in openings, 8, 9, in opposite sidesof the wall near the small end. Preferably the opening, 8, is round andthe'opening, 9, is elongated in the direction of the circumference. Thepin, 7, which "is. passed through these openings, being ofi'set at bothends, indicated by reference characters, 10,

' at the upper end, and 11, at the lower end,

the upper end, 10, being in the form of "a goose neck or return bend,providing a lever arm, 12, by which the pin may be rotated, z. e., thepin is to be inserted from the top through the opening, 8, and thenthrough the opening, 9, the offset ends being turned parallel to thewall of the header. The lower opening, 9, being elongated, provides forthepassage of the offset end, 11. The opening, 8, need not be elongatedas the pin may be inclined to pass the offset at this point. Theoffsets, 10 and 11, are slightly greater than the distance oftheopenings, 8, 9, from the wall of the header, so that when the pinisrotated to the position, which it is shown as occupying in Fig. 1, theplug is drawn closer to its seat, and held by a considerable springtension, the lever arm, being provided for engagement by the hand orwrench in rotating the pin.

In Fig. 3, we have shown, in addition to the outer wall of the header,1, a tube plate, 14:, and the tube, .15. In this instance the plug, 4,which is frustoconical, as described in connection with 'theform shownin Fig. 1, is threaded at its outer end at 16, and this threaded portionis engaged by a threaded nut or ring, 17, which in turn has a bearingsurface, 18, which engages the outer face, 6. of the header wall,drawing the plug into engagement with the opening, and preventingdisplacement of the plug by accidental shocks or blows, or explosionsbetween the head and the cover doors and the like. This plug, as well asthe one shown in Fig. 1, is intended to be inserted from within.

We have thus described, specifically and in detail, a hand hole coverembodying our invention in the preferred, and in a secondary form. Thisdescription is specific and in detail in order that the nature of theinvention and its application may be so clearly understood as to enablethose skilledin the art to practise the invention. However the specificterms herein are used descriptively rather than in the limiting sense,the scope of the invention being defined in the claims.

What we claim and desire to secure by Letters Patent is:

1. In combination a hand hole cover consisting of a tapered plug adaptedto be inserted in a hand hole from within, means for holding said plugand preventing its displacement toward the inside of the headerconsisting of apin passing through the end of the plug, having both endsoffset in the same direction, and means for rotating the pin to bringthe offset ends in contact with the header wall, applying tension to theplug, tending to draw it outward.

2. A hand hole cover consisting of a frustoconical plug adapted to beinserted small end first from within the header so that the small end ofthe plug protrudes outward beyond the header wall and a spring pinextending through the small end of the plug outside the wall and offsetat both ends so that both ends engage the header wall pre- 10 Ventingthe plug from becoming unseated.

Signed by us at W'oodriver, Illinois, this 15th day of December, 1919.

WILLIAM W. HOLLAND. FRANK J. GAINER. Witnesses:

G. R. WAGNER, E. H. PAYNE.

